CMOS image sensors aim for true machine vision

Portland, Ore.  Now that automobiles are beeping to alert you of obstacles while backing up, giving you directions on where to turn, and parallel-parking "hands free," you might have thought that machine vision had already been perfected. Such is not the case.

In fact, all of the above applications are using make-shift technologies that substitute for true machine vision. New CMOS imager chips are emerging that directly sense depth3D pixel-by-pixelenabling machine vision to realize its goal of perceiving objects, and reacting appropriately.

The automotive sensor market already tops $2.5 billion, according to ABI Research (Oyster Bay, N.Y.). Another $750 million is divided among security, industrial automation and videogaming uses of electronic sensors, according to Frost & Sullivan, the Automated Imaging Association and Piper Jaffray, respectively.

Current automotive systems calculate distance, such as those that warn drivers of obstacle behind them as they back up, by using ultrasonic sensors. More sophisticatedexpensivesensors are under development using radar and lidar, but companies worldwide are trying to find cheaper ways to use cameras to calculate distance. Cell phones have invoked economy-of-scale enabling digital cameras to rival analog sensors in cost.

"Cameras are becoming so inexpensive that everybody in the business is trying to use them instead of more expensive ultrasonic, lidar and radar sensors," said David Alexander, senior analyst at ABI Research. "The other motivation for going to cameras, is that different driver assistance applications could potentially share the same camera and even the specialized computer chips and software needed to calculate distance."

"We already have 2D cameras which are used to provide lane-departure warningsthe camera looks out the front and tracks the dotted line. Cameras are also looking out and reading speed limit signs. Cameras can also look in your blind spot and alert you if a vehicle is about to overtake you," said Alexander. "A new application might be pre-crash sensing that calculates that a crash is imminent and pre-charged the brakes as well as fires the air bags more quickly than when waiting for the crash to happen."